def chats(self):
'''
Aimed at the ChatService.
Goal: return a sorted list of ChatServices for every participation of the current user , based on the date n time of the activity.
Returns:a sorted list of ChatServices(id=participation.chat.id) for every participation of the current user if the current user is in the chat with an id = <identification>.
'''
return sorted(tuple(
service.ChatService(id=participation.chat.id)
for participation in self.__instance.participations.all()),
key=lambda chat: chat.activity_dnt,
reverse=True) if self.__instance else None
def establish_a_chat(self, name):
'''
Aimed at the ChatService.
Goal: create a chat instance , by creating an instance of a ChatService.
Arguments: identification:int.
Actions: check if the current user's isinstance exists and create a ChatService instance with provided data.
If such instance has been successfully created return the ChatService instance
Returns: return the instance of the ChatService - If the Actions are all valid and follow the conditions , otherwise - None
'''
return (chat if (chat := service.ChatService()).create(
creator_id=self.__instance.id, name=name) else
None) if self.__instance else None
def get_a_chat(self, identification):
'''
Aimed at the ChatService.
Goal: return a ChatService instance.
Arguments: identification:int.
Actions:if the current user's instance exists, then try to find a participation with a chat_id = <identification>. If there is such a participation establish a ChatService with an id of provided identification.
Returns: ChatService(id=<identification>) if the current user is in the chat with an id = <identification>.
Exceptions:
Raises:
TypeError - if the data type of the identification is not an integer.
'''
assert isinstance(
identification,
int), TypeError('Chat identification shall be an integer.')
return service.ChatService(
id=participation.chat_id) if self.__instance and (
participation := self.__instance.participations.filter_by(
chat_id=identification).first()) else None
def join_a_chat(self, identification):
'''
Aimed at the ChatService.
Goal: join an existing chat instance , by creating a Participant instance using the ParticipantService.
Arguments: identification:int.
Actions: check if the current user's isinstance exists, verify the existance of the chat with such id , after that check if the current user is not a participant of the chat, thus verifying the absence of any related participation.
Then create a Participation instance using the ParticipationService.
Returns: True - If the Actions are all valid and follow the conditions , otherwise - False
Exceptions:
Raises:
ValueError - if the data type of the identification is not an integer.
'''
assert isinstance(
identification,
int), ValueError('Chat identification shall be an integer.')
return True if self.__instance and (chat := service.ChatService(
id=identification)).id == identification and (
not self in chat) and (participation :=
service.ParticipationService()).create(
participant_id=self.__instance.id,
chat_id=identification) else False
def chat(self): ''' Goal:return the chat which contains current message. Returns:ChatService of the chat If the inner instance of the message exists else None ''' return service.ChatService(id=self.__instance.chat_id) if self.__instance else None